In vitro comparison of the erythrocyte sedimenting properties of dextran, hydroxyethyl starch and a new low-molecular-weight hydroxyethyl starch.

A low-molecular-weight preparation of hydroxyethyl starch (LMW-HES) may serve as a desirable substitute for the erythrocyte sedimenting agents presently employed to improve neutrophil yields in centrifugation and gravity leukapheresis. The cell-separating and erythrocyte-sedimenting properties of LMW-HES, assessed in vitro by the recovery of various blood cells in plasma supernatant fluids, were similar to those of the higher-molecular-weight hydroxyethyl starch in current use and to dextran under a variety of conditions. These data predict success for LMW-HES as a sedimenting agent in leukapheresis and recommend that it be evaluated in clinical trials.